Extruded or injection molded products comprising two or more layers of polymer material are typically produced using complex molding or extrusion equipment and/or requiring complex processing steps that are difficult to reproduce from one extrusion or molding cycle to the next cycle. Processing methods for producing products comprised of polymer materials are typically developed by trial and error experimentation with a variety of different polymer materials having specific properties and molecular weights which, once determined are specific to production of the desired product and cannot be varied without substantially changing the end product.